DESCRIPTION: The principal investigator proposes a model of infants' learning about the physical world in which infants are born with a specialized learning mechanism that guides their acquisition of physical knowledge. This mechanism is thought to be responsible for two processes: (1) the formation of event categories that correspond to distinct ways in which objects behave, and (2) the identification of an initial concept and later on the elaboration of variables that affect each event category. When learning about an event category, infants first form a preliminary, all-or-none concept that captures only the essence of the category. With further experience, this initial concept is progressively elaborated. Infants slowly identify variables that are relevant to the category and incorporate this additional knowledge into their reasoning, resulting in increasingly accurate predictions over time. In past research the principal investigator has pursued the nature of the learning mechanism that directs infants' formation of event categories and identification of variables. She has examined different event categories to trace and compare their respective developmental courses. She has also attempted to "teach" infants variables they have not yet identified by presenting them with pertinent observations. She plans to continue these lines of research, as well as undertaking a new line of research to examine whether infants can demonstrate in object-manipulation tasks the same physical knowledge that has been uncovered in visual-attention tasks.